If post ID has_term?

by

The 3rd parameter of has_term() accepts a WP_Post or Post ID. Docs on has_term(). In your example code, it would look like this:

<?php $postid = $_GET['post_id'];
if( has_term( 'campaign', 'type', $postid ) ): ?>
//Do something
<?php endif; ?>

Where campaign would be the term, type would be the taxonomy, and $postid is the post that may have the campaign term.